Methods and Apparatus for Sclerosing the Wall of a Varicose Vein

ABSTRACT

A preferred apparatus for delivering an intravascular drug such as a sclerosing agent (or a microfoam sclerosing agent) to a varicose vein includes a catheter having three concentric tubes. The innermost tube has a guide wire lumen and an inflation lumen. The distal end of the innermost tube has an integral inflatable occlusion balloon in fluid communication with the inflation lumen. The intermediate tube has a lumen through which the innermost tube extends. The distal end of the intermediate tube has a self-expanding balloon with a plurality of fluid pores in fluid communication with the intermediate tube lumen. The outer tube has a lumen through which the intermediate tube extends. Sclerosing agent is dispensed through the intermediate tube to pores located at the distal end of the intermediate tube or in the self-expanding balloon. Veins are sclerosed as the self-expanding balloon is pulled through and ultimately out of the vein.

This application is a division of serial number 09/898,867, filed Jul.3, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to the treatment and correction of venousinsufficiency or varicose veins. More particularly the invention relatesto a minimally invasive procedure using a catheter-based system tosclerose the wall of the vein.

2. State of the Art

The human venous system of the lower limbs consists essentially of thesuperficial venous system and the deep venous system with perforatingveins connecting the two systems. The superficial system includes thelong or great saphenous vein and the short saphenous vein. The deepvenous system includes the anterior and posterior tibial veins whichunite to form the popliteal vein, which in turn becomes the femoral veinwhen joined by the short saphenous vein.

The venous systems contain numerous one-way valves for directing bloodflow back to the heart. Venous valves are usually bicuspid valves, witheach cusp forming a sack or reservoir for blood which, under pressure,forces the free surfaces of the cusps together to prevent retrogradeflow of the blood and allow antegrade flow to the heart. An incompetentvalve is a valve which is unable to close because the cusps do not forma proper seal and retrograde flow of blood cannot be stopped.

Incompetence in the venous system can result from vein dilation.Separation of the cusps of the venous valve at the commissure may occuras a result. Two venous diseases which often involve vein dilation arevaricose veins and chronic venous insufficiency.

The varicose vein condition includes dilatation and tortuosity of thesuperficial veins of the lower limb, resulting in unsightlydiscoloration, pain and ulceration. Varicose veins often involveincompetence of one or more venous valves, which allow reflux of bloodfrom the deep venous system to the superficial venous system or refluxwithin the superficial system.

Varicose veins are compatible with long life and rarely cause fatalcomplications, but the condition significantly decreases the quality oflife. Patients complain primarily of leg fatigue, dull, aching pains,ankle swelling, and ulcerations. Occasionally, thrombosis occurs indilated subcutaneous channels, resulting in local pain, induration,edema, inflammation, and disability. In addition to those problems, thehigh visibility of the unattractive rope-like swellings and reddish skinblotches causes considerable distress for both men and women. Lastly,varicose eczema, which is a local reddened swollen and itching skincondition can occur and can spread to distant parts of the body (calledan “Id reaction”).

Phlebosclerosis, the destruction of venous channels by the injection ofsclerosing agents, has been used to treat varicose veins since 1853,when Cassaignae and Ebout used ferric chloride. Sodium salicylate,quinine, urea, and sodium chloride have also been used, but the agentmore recently favored is sodium tetradecyl sulfate. In order forphlebosclerosis to be effective, it is necessary to evenly dispense thesclerosing agent throughout the wall of the vein without using toxiclevels of the sclerosing agent. This is not particularly difficult forthe smaller veins. However, it is quite difficult or nearly impossiblein larger veins. When a larger vein is injected with a sclerosing agent,the sclerosing agent is quickly diluted by the substantially largervolume of blood which is not present in smaller veins. The result isthat the vein is sclerosed (injured) only in the vicinity of theinjection. If the procedure is continued, and the injections are farapart, the vein often assumes a configuration resembling sausage links.The problem cannot be cured by injecting a more potent solution ofsclerosing agent, because the sclerosing agent may become toxic at sucha concentration.

U.S. Pat. No. 5,676,962 discloses an injectable microfoam containing asclerosing agent. The microfoam is injected into a vein where it expandsand, theoretically, achieves the same results as a larger quantity ofsclerosing agent without the toxicity. Such a foam is presentlymanufactured under the trademark Varisolve® by Provensis, Ltd., London,England. Recent clinical trials of the foam indicate a success rate of81%.

Until recently, the preferred procedure for treating the great saphenousvein was surgical stripping. This highly invasive procedure involvesmaking a 2.5 cm incision in the groin to expose the saphenofemoraljunction, where the great saphenous vein and its branches are doublyligated en masse with a heavy ligature. The distal portion of the veinis exposed through a 1 cm incision anterior to the medial malleolus, anda flat metal or plastic stripper is introduced to exit in the proximalsaphenous vein. The leg is held vertically for 30 seconds to empty thevenous tree before stripping the vein from the ankle to the groin. Ifthe small saphenous vein is also incompetent, it is stripped at the sametime from an incision posterior to the lateral malleolus to thepopliteal space.

After stripping the veins, the leg is held in the vertical position forthree to four minutes to permit vessel ends to retract, constrict, andclot.

After the stripping procedure, collateral veins are removed by theavulsion-extraction technique which is illustrated schematically inprior art FIG. 1. By working through small (5 to 8 mm) transverseincisions, segments of vein 10 to 20 cm long can be removed bydissecting subcutaneously along the vein with a hemostat, and thengrasping, avulsing, and removing the vein. With practice, long segmentsof vein in all quadrants can be removed through these small incisions.No attempt is made to ligate the branches or ends of the veins, sincestripping has shown it to be unnecessary. Bleeding is controlled byelevation and pressure for two to four minutes. As many as 40 incisionsare made in severe cases, but their small size and transverse directionpermit closure with a single suture.

Before closure of the incisions, a rolled towel is rolled repeatedlyfrom the knee to the ankle and from the knee to the groin to express anyclots that may have accumulated. The groin incision is approximated withthree 5-0 nylon mattress sutures and all other incisions are closed witha single suture.

As can be readily appreciated, the stripping and avulsion-extractionprocedures are relatively invasive and require significant anaesthesia.It can therefore be appreciated that it would be desirable to provide analternative, less invasive procedure which would accomplish the sameresults as stripping and avulsion-extraction.

Recently, a number of patents have issued disclosing the treatment ofvaricose veins with RF energy. Illustrative of these recent patents are:U.S. Pat. No. 6,200,312 entitled “Expandable Vein Ligator CatheterHaving Multiple Electrode Leads”; U.S. Pat. No. 6,179,832 entitled“Expandable Catheter Having Two Sets of Electrodes”; U.S. Pat. No.6,165,172 entitled “Expandable Vein Ligator Catheter and Method of Use”;U.S. Pat. No. 6,152,899 entitled “Expandable Catheter Having ImprovedElectrode Design, and Method for Applying Energy”; U.S. Pat. No.6,071,277 entitled “Method and Apparatus for Reducing the Size of aHollow Anatomical Structure”; U.S. Pat. No. 6,036,687 entitled “Methodand Apparatus for Treating Venous Insufficiency”; U.S. Pat. No.6,033,398 entitled “Method and Apparatus for Treating VenousInsufficiency Using Directionally Applied Energy”; U.S. Pat. No.6,014,589 entitled “Catheter Having Expandable Electrodes and AdjustableStent”; U.S. Pat. No. 5,810,847 entitled “Method and Apparatus forMinimally Invasive Treatment of Chronic Venous Insufficiency”; U.S. Pat.No. 5,730,136 entitled “Venous Pump Efficiency Test System And Method”;and U.S. Pat. No. 5,609,598 entitled “Method and Apparatus for MinimallyInvasive Treatment of Chronic Venous Insufficiency”. These patentsgenerally disclose a catheter having an electrode tip which isswitchably coupled to a source of RF energy. The catheter is positionedwithin the vein to be treated, and the electrodes on the catheter aremoved toward one side of the vein. RF energy is applied to causelocalized heating and corresponding shrinkage of the adjacent venoustissue. After treating one section of the vein, the catheter can berepositioned to place the electrodes to treat different sections of thevein.

Although this procedure has gained acceptance and is less invasive thanthe stripping and avulsion-extraction procedures, there are severaldisadvantages to it. In particular, RF treatment is actually quite slowand painful and the patient must be sufficiently anaesthetized along theentire length of the veins to be treated. In addition, repositioning thecatheter is time consuming thus requiring anaesthesia for a prolongedperiod. Moreover, the RF treatment is incomplete, as only a portion ofthe vein wall is actually treated, i.e. the portion contacting theelectrode. The partially treated vein may eventually re-cannularize.Furthermore, tributary veins remain unaffected and must be treatedseparately.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide methods andapparatus for the minimally invasive treatment of varicose veins.

It is also an object of the invention to provide methods and apparatusfor the minimally invasive treatment of varicose veins wherein onlyminimal anaesthesia is required.

It is another object of the invention to provide methods and apparatusfor the minimally invasive treatment of varicose veins wherein tributaryveins are treated simultaneously with the vein to which they connect.

It is an additional object of the invention to provide methods andapparatus for the minimally invasive treatment of varicose veins andconnecting tributaries wherein the entire wall of the vein is evenlysclerosed.

Another object of the invention is to provide methods and apparatus forthe minimally invasive treatment of varicose veins which do not utilizehigh concentration sclerosing agents.

In accord with these objects which will be discussed in detail below, afirst embodiment of the present invention includes a catheter havingthree concentric tubes: an innermost tube, an outer tube, and anintermediate tube. The innermost tube has two lumena: a guide wire lumenand an inflation lumen. The distal end of the innermost tube has anatraumatic tip and an integral inflatable occlusion balloon in fluidcommunication with the inflation lumen. The intermediate tube has asingle lumen through which the innermost tube extends. The distal end ofthe intermediate tube has a self-expanding balloon with a plurality offluid pores in fluid communication with the lumen of the intermediatetube. The outer tube has a single lumen through which the intermediatetube extends. The proximal ends of the innermost and intermediate tubesare provided with fluid fittings. The proximal ends of the outer tubeand the intermediate tube are provided with sealing fittings.

An exemplary treatment method using the first embodiment of theinvention includes elevating the foot above the groin, delivering thecatheter via a guide wire into the saphenous vein from the ankle to thegroin. The patient is then placed in a Trendelenberg position (the bodyinclined downward approximately 30 degrees and the leg elevatedapproximately 60 degrees. The inflatable occlusion balloon is inflatedsufficiently to block blood flow, and moving the outer tube relative tothe intermediate tube (or vice versa) such that the self-expandingballoon expands and contacts the wall of the vein. With the inflatableocclusion balloon securely in place, the intermediate and outer tubesare pulled away from the inflatable occlusion balloon while sclerosingagent is injected into the lumen of the intermediate tube. Thesclerosing agent exits the self-expanding balloon through its pores anddirectly contacts the wall of the vein. Pressure exerted by theself-expanding balloon both massages the wall of the vein and squeegeessclerosing agent evenly into the vein wall. Collateral tributary veinsare injected with sclerosing agent as the self-expanding balloon passesover them. The diameter of the self-expanding balloon becomesprogressively smaller as it is moved from the groin area toward theankle because the diameter of the vein changes accordingly. When theentire vein has been sclerosed, the inflatable occlusion balloon isdeflated and the catheter is removed and the incision is sealed. The legis preferably wrapped with a compression bandage for a few days duringwhich the veins flatten out, thereby removing blood from the vein andallowing the walls of the vein to fuse to itself.

According to the exemplary treatment using the first embodiment of thecatheter, only one small incision is made in the ankle and only a smallamount of anesthetic is required at the place of the incision. Theprocedure is relatively painless. Tributary veins are treatedsimultaneously with the vein into which they feed. The entire wall ofthe vein is evenly sclerosed. Because blood flow is blocked andsclerosing agent is applied directly to the wall of the vein, a lowerconcentration of sclerosing agent can be used as it is not diluted byflowing blood. The occlusion balloon also prevents sclerosing agent fromexiting the treated vein and entering into another vein.

According to an alternative embodiment, sclerosing agent may be injectedthrough the lumen of the outer tube. In either case, the self-expandingballoon causes the sclerosing agent to be evenly distributed andmassaged into the wall of the vein.

A second embodiment of the catheter of the invention has four tubes, twoof which are equipped with inflatable occluding balloons. The procedurefor using this embodiment involves inflating one balloon upstream andthe other downstream and moving the self-expanding balloon between them.The two balloons can be inflated to isolate a tributary for sclerosing.

A third embodiment has only one balloon which massages the wall of thevein as sclerosing agent is injected downstream of the balloon.

A fourth embodiment utilizes a brush having hollow bristles to massagethe wall of the vein as sclerosing agent is injected through thebristles.

According to the presently preferred embodiments, a drug dispenserattachment is provided to automatically inject the sclerosing agent asthe self-expanding balloon is moved through the vein. The drugdispenser, which may or may not be disposable, attaches to a disposablesyringe and includes a rack and pinion gear system for engaging theplunger of the syringe. The gear system is driven by a spool carrying afilament, a ribbon, or a cable. The drug dispenser is attached to thepatient's leg with straps and the end of the cable is attached to theintermediate tube of the catheter such that as the self-expandingballoon is moved through the vein, the cable is pulled causing the spoolto rotate and the rack and pinion gears to engage the plunger of thesyringe and dispense the sclerosing agent. Alternatively, the dispensermay be attached to the catheter and the cable attached to the patient'sleg.

In addition to treating varicose veins, the methods and apparatus can beused for the delivery of other intravascular medications such asantiproliferative drugs, for example, Paclitaxel or Rapamycin tocoronary arteries and the like, to prevent restenosis of these vesselsafter stenting. The device can also be used to deliver drugs to otherhollow tubes such as the fallopian tubes or to persistent abnormal sinustracts.

Additional objects and advantages of the invention will become apparentto those skilled in the art upon reference to the detailed descriptiontaken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a prior art technique for thetreatment of varicose veins;

FIG. 2 is a broken side elevation in partial section illustrating afirst embodiment of a catheter according to the invention;

FIG. 3 is a sectional view taken along line A-A of FIG. 2;

FIG. 4 is a view similar to FIG. 2 but illustrating the inflatableocclusion balloon inflated inside a vein;

FIG. 5 is a view similar to FIG. 4 but illustrating the self-expandingballoon expanded inside a vein;

FIG. 6 is a view similar to FIG. 5 but illustrating the self-expandingballoon after having traversed a portion of the vein;

FIG. 7 is a view similar to FIG. 6 but illustrating a second embodimentof the catheter of the invention;

FIG. 8 is a view similar to FIG. 7 but illustrating a third embodimentof the invention;

FIG. 8 a is a view similar to FIG. 8 but illustrating a fourthembodiment of the invention;

FIG. 8 b is an enlarged schematic distal end view of the embodiment ofFIG. 8 a;

FIG. 9 is a perspective view of a drug dispenser according to theinvention;

FIG. 10 is a partially cut away top view of the drug dispenser of FIG.9; and FIG. 11 is an enlarged perspective view of a winding clutch ofthe drug dispenser.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIGS. 2 and 3, a first embodiment of the presentinvention includes a catheter 10 having three concentric tubes: aninnermost tube 12, an outer tube 14, and an intermediate tube 16. Theinnermost tube 12 has two lumens: a guide wire lumen 18 and an inflationlumen 20. The distal end of the innermost tube includes an atraumatictip 22 and an integral inflatable occlusion balloon 24 in fluidcommunication with the inflation lumen 20. The intermediate tube 16 hasa single lumen 26 through which the innermost tube extends. The distalend of the intermediate tube 16 is provided with a self-expandingballoon 28 with a plurality of fluid pores 30 in fluid communicationwith the lumen 26 of the intermediate tube. The outer tube 14 has asingle lumen 32 through which the intermediate tube 16 extends.

The proximal end of the innermost tube 12 has a guide wire hub 34 whichprovides access to the guide wire lumen 18 and a fluid port 36 in fluidcommunication with the inflation lumen 20. The proximal end of theintermediate tube 16 is provided with a fluid port 38 in fluidcommunication with the lumen 26 and two fittings 40, 42. The fitting 40allows the innermost tube 12 and intermediate tube 16 to be movedrelative to each other while maintaining a seal of the annular fluidspace between the innermost tube 12 and intermediate tube 16. It will beappreciated that the proximal end of the tube 16 can be reinforced withmetal tubing such as thin-walled hypodermic tubing to make it easier topush and provide a more uniform sealing surface. The fitting 42 iseither press fit or glued to the proximal end of the intermediate tube16 or attaches to a luer hub which is press fit or glued to the proximalend of the intermediate tube 16. The proximal end of the outer tube 14has a fitting 44 that seals the space between the outer tube 14 and theintermediate tube 16 and also releasably locks their relative positions.

An exemplary treatment method using the first embodiment of theinvention can be understood with reference to FIGS. 4-6. Afteranesthetizing the patient's ankle, a guide wire (not shown) is fed intothe saphenous vein V from the ankle to the groin of the patient. Theguide wire can be fed from a cut-down to the vein at the ankle or byusing percutaneous entry techniques well known in the art whichgenerally involves the use of a catheter sheath introducer, and thelike. Once the guide wire is in place, the catheter assembly 10 isthreaded over the guide wire and follows the guide wire up the leg suchthat the tip 22 of the occlusion balloon 24 is located in a desiredlocation, e.g., just proximal to the exit of the saphenous vein in thevicinity of the profunda vein. The exact location of the occlusionballoon can be identified by ultrasound, palpation, or by angiography,and the like. The occlusion balloon 24 is then inflated with a gas orfluid through the port 36. CO₂ gas is the preferred inflator because itis easy to see with ultrasound and it is safely absorbed into the bloodstream should any leakage occur. Once the occlusion balloon 24 isinflated, blood can no longer pass to or from the saphenous vein V viathe profunda vein (not shown).

With the inflated occlusion balloon in place, as is shown in FIGS. 4 and5, the fitting 44 of the outermost tube 14 is loosened and the tube 14is slid backwards over intermediate tube 16 such that the fitting 44butts up against connector fitting 42 as shown in FIG. 5. Retracting theouter tube 14 in this manner releases self-expanding balloon 28, whichself-expands until it hits the wall of the varicose vein V.

According to the presently preferred embodiment, the self-expandingballoon 28 is made of a braided mesh, which is braided such that itspreferred stable state is fully expanded. The wires of the mesh are of aspring material such as stainless steel, cobalt-chrome-nickel (Elgiloywire), nitinol or the like. Alternatively, the self-expanding balloonwires may be made of a plastic such as PET, PMMA, polyurethane, nylon orthe like. The wires may or may not be heat hardened to impart greaterspring-like properties and memory to the mesh. Filling the spacesbetween the braid wires is a thin membrane 49 made from an elastomericmaterial such as polyurethane, silicone rubber, polyolefin, polyamidecopolymers and the like. The membrane can be formed by dip molding,insert molding or it can be formed separately and glued in place. Thoseskilled in the art will appreciate that the self-expanding balloon bothshortens in length and widens in diameter as it achieves its preferredexpanded state. It will be appreciated that the distal end of theballoon 28 is dimensioned such that it can move over the inner tube 12but still maintain a fluid seal between the balloon 28 and the tube 12.As illustrated in FIGS. 4-6, a plurality of fluid pores 30 in themembrane 49 are located about the circumference of the balloon 28.

When the catheter 10 is in the position shown in FIG. 5, a source ofsclerosing agent (or a microfoam containing a sclerosing agent) iscoupled to the port 38 and operated to allow sclerosing agent to flowthrough the annular space between the tubes 12 and 16, into the balloon28 and out through the pores 30. It will be appreciated that sclerosingagent so dispensed with flow directly into the wall of the vein V.According to the invention, as sclerosing agent is being dispensed, theself-expanding balloon 28 is moved away from the balloon 24 as shown inFIG. 6 by moving the tubes 14 and 16 relative to the tube 12. It will beappreciated that as the balloon 28 is moved along the length of thetapering vein V, the balloon decreases in diameter and lengthens. Thesclerosing agent exiting the pores 30 is massaged or “squeegeed” intothe wall of the vein V by means of the outward pressure exerted by theballoon 28 against the wall of the vessel V.

FIG. 6 shows the occlusion balloon 24 remaining in place as theself-expanding balloon 28 has traversed along a length of the vessel V.Sclerosing agent is continually injected through the balloon 28 as it iswithdrawn. It can also be appreciated that as the balloon 28 passescollateral (tributary) veins such as those identified as T1 and T2,sclerosing agent fills the collateral veins to effectively cause them tosclerose. It will be appreciated that additional sclerosing agent can beinjected into the tributary veins by means of a second syringe fluidlycoupled to the inlet port 38 by means of a T-connector According to thepresently preferred embodiment, the balloon 28 is withdrawn through theentire length of the vein V to be sclerosed. When the entire length istraversed, the occlusion balloon 24 is deflated, the catheter 10 isremoved and the puncture site is sealed. Simultaneous with the removalof the occlusion balloon, or just prior to deflation of the balloon, oreven during the procedure, the leg of the patient is preferably wrappedwith an elastic compression bandage, e.g, an ACE BANDAGE, with othercompression objects such as foam, etc. Wrapping the leg in this mannercauses the vein to flatten-out, thereby removing blood from the vein andallowing the lumen to fuse to itself in the collapsed embodiment. Aftera few days of compression the bandages are removed and the vein is nolonger medically or cosmetically problematic.

It has been discovered that, due to the “squeegee-like” action of theself-expanding balloon 28, the sclerosing agent need not be dispensed atthe outer circumference of the balloon. Thus, the pores 30 of theballoon may be located on the proximal portion of the balloon.Alternatively, the balloon need not have any pores, but pores may beprovided at the distal end of the tube 16. As yet another alternative,neither the balloon nor the intermediate tube are provided with pores,but the sclerosing agent is provided via the outer tube 14. In allcases, the sclerosing agent will flow or be forced toward the wall ofthe vein and be massaged into the vein wall by the balloon 28.

Those skilled in the art will appreciate that if the sclerosing agent isnot injected through the balloon 28, the balloon need not beself-expanding. It could be an inflatable balloon which is inflated witha gas or a saline solution from an IV bag, etc. In this embodiment, thepressure can be adjusted as the balloon traverses the vein and thediameter of the vein changes.

As mentioned above, the catheter of the invention can be used to deliverother types of intravascular medication directly to the wall of a vein.Although the treatment of varicose veins generally involves treating theentire length of the vein, other treatments may require or prefer thatonly a selected portion of the blood vessel be treated. Accordingly, asecond embodiment of the invention is illustrated in FIG. 7 in which twoinflatable occlusion balloons are provided to isolate a region of ablood vessel for treatment.

As shown in FIG. 7, the catheter 110 has four tubes: an innermost tube112, an outer tube 114, and two intermediate tubes 116 and 117. Theinnermost tube 112 has an inflatable balloon 124 with an atraumatic tip122 at its distal end. The innermost tube 112 is substantially the sameas the tube 12 described above. The outer tube 114 and intermediate tube116 are also substantially the same as the tubes 14 and 16 describedabove. The additional tube 117 resides in the annular space between thetubes 114 and 116. It has an inflatable balloon 125 at its distal endand is similar to the tube 112 in that it has two lumen, one of whichcarries the tube 116 and the other of which is used to inflate theballoon 125. The procedure for using this embodiment involves inflatingone balloon upstream and the other downstream and moving theself-expanding balloon between them while injecting an intravasculardrug. This allows treatment of a selected portion of a blood vesselwithout diluting the treatment drug. It will also be appreciated thatthe catheter 110 can also be used to isolate one or a plurality oftributary veins by inflating the balloons on opposite sides of thetributary or tributaries. Sclerosing agent is then injected between theballoons and forced into the tributary or tributaries,

A third embodiment of a catheter 210 according to the invention is shownin FIG. 8. This embodiment includes an outer tube 214 and an inner tube216. The distal end of the inner tube 216 is provided with aself-expanding balloon 228. According to this embodiment, the balloon228 is optionally provided with an abrasive surface 231 and/or pores(not shown). When an abrasive surface is provided, the catheter 210 maybe used with or without a sclerosing agent. In these instances,treatment may consist of abrading the wall of the blood vessel with theabrasive surface 231 of the balloon 228. In other instances, where poresare provided in the balloon, treatment may consist of abrading the wallof the vain (if the balloon has an abrasive surface) as the sclerosingagent is injected out of the pores. In yet other instances, when nopores are provided in the balloon, treatment may include injecting anintravascular drug through the annular space between the outer tube 214and the inner tube 216 or through pores (not shown) at the distal end ofthe inner tube 216. If the balloon 228 is moved against the flow of thedrug (from right to left as seen in FIG. 8), the drug will be massagedinto the wall of the blood vessel (which is abraded if the balloon hasan abrasive surface) by the balloon 228.

A fourth embodiment of a catheter 410 according to the invention isshown in FIGS. 8 a and 8 b . This embodiment includes an outer tube 414and an inner tube 416. The distal end of the inner tube 416 is providedwith a brush 430 having a plurality of hollow bristles, e.g. 430 a-430 pand a plug 418. The hollow bristles are in fluid communication with theinner tube 416 such that a sclerosing agent may be injected through thetube 416 and exit the ends of the bristles. The bristles 430 a-420 p arepreferably made of a resilient material so that they will expand to theposition shown in the Figures, i.e., approximately radial to the innertube, when released from the outer tube. A method for using the fourthembodiment includes moving the outer tube and/or inner tube until thebristles 430 a-420 p are collapsed inside the outer tube, delivering thetwo tubes to a procedural site in a blood vessel, moving the outer tubeand/or inner tube until the bristles 430 a-420 p are expanded as shownin the figures, then moving the inner tube relative to the blood vesselwhile injecting a sclerosing agent through the inner tube and thebristles.

According to the presently preferred embodiments, a drug dispenserattachment is provided to automatically inject the sclerosing agent asthe self-expanding balloon is moved through the vein. FIG. 9 shows athree dimensional view of a drug dispenser 300 with a body 302 defininga channel for receiving a disposable syringe 304, an injector cam 306, astring 308 with a hook 309, a winding clutch 310 (shown in furtherdetail in FIG. 11) and slots 312.

FIG. 10 is a partially cut away top view of the dispenser 300. As shownin FIG. 10, the string 308 with hook 309 is wound on spool 314. Thespool 314 is rigidly attached to the winding clutch 310 and clutchinglyattached to an axle 316. The axle 316 is rigidly attached to a spur gear318. The spur gear 318 engages a second spur gear 320, which in turn isrigidly attached to an axle 322 which carries a pinion gear 324. Thepinion gear 324 engages a rack 326, which is attached to the injectorcam 306. As seen in FIG. 10, the injector cam 306 is aligned with theplunger 305 of the disposable syringe 304.

As seen in FIG. 11, the winding clutch 310 includes a clutch housing 328and a cam 330. The clutch housing 328 defines a center hole 332 throughwhich the axle (316 in FIG. 10) extends. The cam 330 defines a hole 334with an adjacent keyway 336. The cam 330 is spring biased by a spring338 so that the keyway 336 aligns with the hole 332 and engages flats(not shown) which are machined on the axle (316 in FIG. 10). When thecam 330 is pressed at 340, the hole 334 lines up with the hole 332 andthe flats on the axle are no longer engaged causing clutch 310 to rotatewithout engaging the axle and without dispensing sclerosing agent fromsyringe 304. This feature allows the string 305 to be wound onto thespool 314. It also provides the surgeon with a mechanism to lengthen orshorten the string without dispensing sclerosing agent from the syringe.

The drug dispenser 300 works as follows. The body 302, with the exit ofthe syringe 304 pointed towards the patient's foot, is fastened to thepatient's leg, preferably adjacent the ankle, via straps such as VELCROstraps which are fed through the slots 312. The sclerosing catheter(e.g. 10 in FIG. 2) is maneuvered into the patient's vein from apuncture site in the patient's ankle. The proximal hub 42 (FIG. 2) ofthe sclerosing catheter is attached to the hook 309 at the end of thestring 308. As the sclerosing catheter is pulled out of the vein,tension on string 308 causes pulley 314 to rotate which causes thepinion 324 to rotate (via gears 318 and 320) and rack 326 to move. Thecam 306 on the rack 326 presses the plunger 305 causing sclerosing agentto be discharged from syringe 304. Those skilled in the art willappreciate that a fluid conduit may be required to couple the fluid exitof the syringe 304 to the fluid port 38 (FIGS. 2, 4, and 5). It willalso be appreciated that the gear ratios of the drug dispenser can beselected such that the appropriate volume of sclerosing agent dispensesas the catheter is pulled out of the leg. The main purpose of theinjector is to allow the physician to dispense a continuous amount ofsclerosing agent into the patient as a function of the withdrawal of thecatheter. It can be appreciated that no sclerosing agent is dischargedif the catheter is not pulled and that the flow rate of sclerosing agenttracks the speed at which the catheter is withdrawn. As mentioned above,the drug dispenser can be used in conjunction with one of the cathetersto dispense other kinds of intravascular drugs for different procedures.

Those skilled in the art will appreciate that the drug dispenser may beattached to the catheter and the string attached to the patient's leg.Moreover, it will be appreciated that the clutch may be omitted if anadjustable length cable is used. It will also be appreciated that othertypes of clutches could be used at any of the gears or axles.

There have been described and illustrated herein several embodiments ofmethods and apparatus for sclerosing the wall of a varicose vein. Whileparticular embodiments of the invention have been described, it is notintended that the invention be limited thereto, as it is intended thatthe invention be as broad in scope as the art will allow and that thespecification be read likewise. For example, the catheter can beprovided with an integral guide wire and the catheter and the guide wirecan be inserted simultaneously. Also, the dual lumen catheter can beformed by two concentric tubes with the inflation lumen being theannular space between the tubes. It will therefore be appreciated bythose skilled in the art that yet other modifications could be made tothe provided invention without deviating from its spirit and scope as soclaimed.

1. An apparatus for delivering an intravascular drug, said apparatuscomprising: a) a first catheter tube having a proximal end, a distalend, and a fluid lumen extending from its proximal end to its distalend; b) an inflatable balloon coupled to said distal end of said firstcatheter and in fluid communication with said fluid lumen; c) a secondcatheter tube having a proximal end, a distal end, and a lumen extendingfrom its proximal end to its distal end, said first catheter tubeextending through said lumen of said second catheter tube; d) aself-expanding balloon coupled to said distal end of said secondcatheter tube, said first catheter tube extending through saidself-expanding balloon; and e) a third catheter tube having a proximalend, a distal end, and a lumen extending from its proximal end to itsdistal end, said second catheter tube extending through said lumen ofsaid third catheter tube, wherein at least one of said second cathetertube and said third catheter tube is adapted to receive and deliver theintravascular drug to the location of said self-expanding balloon.
 2. Anapparatus according to claim 1, wherein: said first catheter tube has aguide wire lumen extending from its proximal end to its distal end. 3.An apparatus according to claim 1, wherein: said second catheter tube isadapted to receive and deliver the intravascular drug, and saidself-expanding balloon includes a plurality of fluid pores, said fluidpores being in fluid communication with said lumen of said secondcatheter tube.
 4. An apparatus according to claim 1, wherein: saidsecond catheter tube is adapted to receive and deliver the intravasculardrug, and said distal end of said lumen of said second catheter tube hasa plurality of fluid pores.
 5. An apparatus according to claim 1,wherein: said third catheter tube is adapted to receive and deliver theintravascular drug.
 6. An apparatus according to claim 1, wherein: saidthird catheter tube has a proximal locking means for locking thelocation of said second catheter tube relative to said third cathetertube.
 7. An apparatus according to claim 1, wherein: said first cathetertube is adapted to receive the intravascular drug by having a proximalport in fluid communication with said fluid lumen of said first cathetertube.
 8. An apparatus according to claim 1, wherein: said secondcatheter tube is adapted to receive the intravascular drug by having aproximal port at said proximal end of said second catheter tube in fluidcommunication with said fluid lumen of said second catheter tube.
 9. Anapparatus according to claim 1, further comprising: f) a fourth cathetertube having a proximal end, a distal end, and a lumen extending from itsproximal end to its distal end, said third catheter tube extendingthrough said lumen of said fourth catheter tube; and g) a secondinflatable balloon coupled to the distal end of said fourth catheter.10. An apparatus according to claim 1, further comprising: f) a drugdispenser having a drug reservoir and a drug outlet, said drug outletbeing fluidly coupled to said fluid delivery means, said drug dispenserbeing adapted to automatically dispense the drug from the reservoir intothe fluid delivery means as said second catheter tube is moved through ablood vessel.
 11. An apparatus according to claim 10, wherein: said drugreservoir is a syringe having a plunger, and said drug dispenserincludes means for moving said plunger as said second catheter tube ismoved through a blood vessel.
 12. An apparatus according to claim 11,wherein: said means for moving said plunger includes a gear coupled tosaid plunger, a spool coupled to said gear, and a filament, ribbon, orcable coupled to said spool.
 13. An apparatus according to claim 10,wherein: said drug dispenser includes means for coupling said drugreservoir to a patient's limb.
 14. An apparatus according to claim 10,wherein: said drug dispenser includes means for coupling said drugreservoir to one of said catheter tubes.
 15. An apparatus for deliveringan intravascular drug, said apparatus comprising: a) a catheter having aproximal end, a distal end, and a lumen extending from its proximal endto its distal end; b) a drug reservoir having a drug outlet, said drugoutlet being fluidly coupled to the proximal end of the lumen of thecatheter, c) dispensing means coupled to said drug reservoir, saiddispensing means being adapted to automatically dispense the drug fromthe reservoir into the lumen of the catheter as the catheter is movedthrough a blood vessel.
 16. An apparatus according to claim 15, wherein:said drug reservoir is a syringe having a plunger, and said dispensingmeans includes means for moving said plunger as said catheter is movedthrough a blood vessel.
 17. An apparatus according to claim 16, wherein:said means for moving said plunger includes a gear coupled to saidplunger, a spool coupled to said gear, and a filament or cable coupledto said spool.
 18. An apparatus according to claim 15, furthercomprising: d) attachment means for attaching said drug reservoir to apatient's limb.
 19. An apparatus according to claim 15, furthercomprising: d) attachment means for attaching said drug reservoir tosaid catheter.
 20. An apparatus for delivering an intravascular drug,said apparatus comprising: a) a first catheter tube having a proximalend, a distal end, and a lumen extending from its proximal end to itsdistal end; b) a self-expanding balloon coupled to said distal end ofsaid first catheter tube; and c) a second catheter tube having aproximal end, a distal end, and a lumen extending from its proximal endto its distal end, said first catheter tube extending through said lumenof said second catheter tube, wherein at least one of said firstcatheter tube and said self-expanding balloon includes pores, and saidfirst catheter tube is adapted to receive and deliver the intravasculardrug to said pores.
 21. An apparatus according to claim 20, wherein:said self-expanding balloon is comprised of spring wires and a thinmembrane coupled to said spring wires.
 22. An apparatus according toclaim 20, wherein: said self-expanding balloon includes an abrasiveouter surface.
 23. An apparatus according to claim 20, wherein: saidself-expanding balloon is made of plastic.
 24. An intravascularapparatus, comprising: a) a first catheter tube having a proximal end, adistal end, and a lumen extending from its proximal end to its distalend; b) a self-expanding balloon coupled to said distal end of saidsecond catheter tube and having an abrasive outer surface; and c) asecond catheter tube having a proximal end, a distal end, and a lumenextending from its proximal end to its distal end, said first cathetertube extending through said lumen of said second catheter tube.
 25. Anintravascular apparatus according to claim 24, wherein: at least one ofsaid first catheter tube and said self-expanding balloon includes pores,and said first catheter tube is adapted to receive and deliver anintravascular drug to said pores.
 26. A kit for the intravasculartreatment of a blood vessel, said kit comprising: a) a catheter havingan expandable balloon at its distal end and a drug delivery lumen; andb) a drug dispenser having a drug reservoir fluidly coupled to said drugdelivery lumen, wherein said drug dispenser includes means forautomatically dispensing a drug from said drug reservoir into said drugdelivery lumen in response to movement of said catheter through theblood vessel.
 27. A kit according to claim 26, wherein: said drugreservoir includes a syringe having a plunger and said means forautomatically dispensing includes means for depressing said plunger. 28.An apparatus for delivering an intravascular drug, said apparatuscomprising: a) a first catheter tube having a proximal end, a distalend, and a first lumen extending from its proximal end to its distalend; b) a first inflatable balloon coupled to said distal end of saidfirst catheter and in fluid communication with said first lumen; c) asecond catheter tube having a proximal end, a distal end, and a secondlumen extending from its proximal end to its distal end, said firstcatheter tube extending through said second lumen; d) a secondinflatable balloon coupled to said distal end of said second cathetertube and in fluid communication with said second lumen; and e) a thirdcatheter tube having a proximal end, a distal end, and a third lumenextending from its proximal end to its distal end, said second cathetertube extending through said third lumen, wherein said third lumen isadapted to receive and deliver the intravascular drug to the location ofsaid second inflatable balloon.
 29. An apparatus for delivering anintravascular drug, said apparatus comprising: a) a first catheter tubehaving a proximal end, a distal end, and a lumen extending from itsproximal end to its distal end; and b) a brush having a plurality ofhollow bristles coupled to said distal end of said first catheter tubeand being in fluid communication with said lumen, wherein said firstcatheter tube includes means for injecting a vascular drug into saidlumen such that the drug exits through said hollow bristles of saidbrush.
 30. An apparatus according to claim 29, further comprising: c) asecond catheter tube having a proximal end, a distal end, and a lumenextending from its proximal end to its distal end, said first cathetertube extending through said lumen of said second catheter tube.
 31. Anapparatus according to claim 11, wherein: said means for moving saidplunger includes a filament, pull wire, ribbon, or cable.
 32. Anapparatus according to claim 16, wherein: said means for moving saidplunger includes a filament, pull wire, ribbon, or cable.
 33. Anapparatus according to claim 32, further comprising: d) attachment meansfor attaching said drug reservoir to a patient's limb.
 34. An apparatusaccording to claim 32, further comprising: d) attachment means forattaching said drug reservoir to said catheter.